Method and apparatus for producing wearing article

ABSTRACT

A method for producing a wearing article of the present invention includes the steps of: supplying an elastic member; stretching the elastic member; placing the stretched elastic member so that the elastic member spreads across a plurality of first webs divided in a transport direction; making a part of a second web loose in the transport direction while transporting the second web, thereby forming a loose portion; placing the first webs, on which the elastic member is disposed, on non-loose portions before and after the loose portion of the second web; and cutting the elastic member between adjacent first webs of the plurality of first webs.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation of commonly assigned,copending application Ser. No. 10/316,523, filed Dec. 11, 2002, andentitled “Method and Apparatus for Producing Wearing Article”, theentire disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method and apparatus for producing adisposable wearing article such as paper diapers and pants.

2. Description of the Related Art

In the above-mentioned type of wearing articles, in order to form, forexample, a waist gathering, an elastic member is placed on a sheetsurface. However, such an elastic member allows an absorber to shrink,so that the absorber becomes stiff, degrading a feeling of wearing.

As a prior art of cutting an elastic member, Japanese Laid-Open PatentPublication No. 2001-224627 discloses a method for interposing a filmsheet for gathering between a peripheral surface of an adsorbent rollerand a cutter blade of a cutter roller, and cutting the film sheet.

Furthermore, International publication No. WO 00/04855 discloses amethod for forming a web loop.

Japanese Laid-Open Patent Publication No. 63-317576, for example,discloses a movement of a plurality of pads rotating about apredetermined axis while each of the pads changes its velocity, during aprocess of producing a worn article or a web (a continuous material).Japanese National Phase PCT Laid-Open Publication No. 2000-514024discloses a material engagement member reciprocating in a directionparallel to a rotation axis of a drum.

When each of the pads is supported by a bearing, the same number ofbearings as the number of pads are required so that the velocities ofthe pads can be changed individually, thereby increasing the size and/orcomplexity of the device.

SUMMARY OF THE INVENTION

In view of the problem in the prior art, it is an object of the presentinvention to provide a rotation device having a simple structure andbeing capable of providing a complicated movement. It is also an objectof the present invention to provide a method for transferring a wornarticle, a method for folding a web and a device for folding a web thatcan suitably employ the rotation device, and a disposable worn articleproduced by using the same.

In order to achieve the objects set forth above, a first rotation deviceof the present invention includes: an endless guide; a plurality ofmoving sections that slide while being guided by the guide; and arotation member that allows the guide to rotate about an axis. Inaddition, the plurality of moving sections are arranged in the rotationallowance direction of the rotation member; and the plurality of movingsections can slide in the direction of rotation of the rotation memberor in the opposite direction by being guided by the guide.

A second rotation device of the present invention includes: a pluralityof guides; a plurality of moving sections that slide while being guidedby the plurality of guides; and a rotation member that allows theplurality of guides to rotate about an axis. Furthermore each of themoving sections is guided by at least one of the guides; and theplurality of guides is provided about the axis so as to be arranged inthe rotation allowance direction of the rotation member whilesurrounding the axis, so that the plurality of moving sections can slidein the direction of rotation of the rotation member or the oppositedirection.

As a rotational force having a predetermined velocity curve is appliedto the moving sections, the rotation member rotates at a high velocityalong with the rotation of the moving sections. Meanwhile, each movingsection rotates with respect to the guide at a low relative velocity. Inthis way, the friction between the moving sections and the guide issignificantly reduced, thereby improving the durability of the device.

Ideally, the rotation member is capable of an unlimited rotation, andmay be a ball bearing or a roller bearing including a rolling elementsuch as a ball or a roller.

The guide may be any type of guide as long as it allows the slidingmovement of the moving sections in a direction including a component ofthe rotation allowance direction of the rotation member. The term“endless guide” as used herein refers to not only a generally completelyring-shaped guide, but also to those having slight gaps in thecircumferential direction, or even to those obtained by arranging guideelements, which together form one guide, so as to be spaced apart fromone another at a predetermined interval. Moreover, the guide elementsmay overlap with one another as viewed in the axial direction. Thephrase “in a direction including a component of the rotation allowancedirection of the rotation member” as used herein means that a guideelement may be provided in an inclined direction. The guide element maybe a rail or a groove.

In the second rotation device of the present invention, the phrase “aplurality of guides” means that the guides are spaced apart from oneanother in the direction of rotation or in the axial direction to such adegree that a moving section cannot move from one guide to another.

Where one moving section moves from one of a plurality of guide elementsto another, the plurality of guide elements together form one guide.

In the present invention, it is preferred to provide a controller forcontrolling the moving velocity of the moving sections. Such acontroller causes the moving sections to rotate at differingpredetermined instantaneous velocities, thereby changing the pitchbetween the moving sections during rotation.

The term “instantaneous velocity” as used herein refers to a velocity ina minute period of time, meaning that each moving section rotates whilechanging its velocity depending on the rotational position thereof.

The present invention can be used with a rotation device as described inPCT International Publication WO01/44086, a method for transferring wornarticles while changing the pitch thereof, a method for folding a web,or a device for folding a web.

A method for folding a web of the present invention is a method forfolding a web by using a rotation device including a plurality of padsthat rotate about a predetermined axis so as to continuously transferthe web. The method includes: supplying the web onto surfaces of therotation device pads; rotating adjacent ones of the pads onto which theweb has been supplied so as to change the interval therebetween toslacken a portion of the web between the adjacent pads, thereby foldingthe portion of the web; and releasing the web from the pads.

Such a folding method can be realized using the first or second rotationdevices of the present invention. Other rotation devices such as thatdescribed in PCT International Publication WO01/44086 may be used inplace of the rotation device including a plurality of pads.

A device for folding a web of the present invention is a device forfolding a web to form a wall in a direction transverse to a web runningdirection. The device includes: a transfer member for forming a slackportion in the web in the running direction thereof while continuouslytransferring the web; and a member for folding the slack portion so asto form the wall.

The term “wall” as used in the present invention refers to a portion ofa web or a sheet-like material that has been folded, regardless ofwhether the wall is laid down along the surface of the web or standingon the web.

In the folding device of the present invention, the “transfer member”may be any member including a plurality of transfer sections fortransferring the web in the web running direction, wherein the transfervelocity of one of the transfer sections is set to be lower than that ofanother transfer section upstream of the one of the transfer sections soas to form a slack portion in a portion of the web between the upstreamand downstream transfer sections.

In the present invention, it is preferred to provide a directioningmember for defining the direction in which a slack portion is to befolded.

In the present invention, the term “slack portion” refers to a portionof a web on which no tension is applied.

In the present invention, it is preferred to provide a fold-holdingsection for maintaining the shape or condition of a folded portionobtained by folding the slack portion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side layout view of an apparatus for producing a wearingarticle of Embodiment 1 according to the present invention.

FIG. 2 is a side layout view illustrating the steps of cutting anelastic member in the apparatus shown in FIG. 1.

FIG. 3A is a perspective view of a stack in a state before the elasticmember is cut, and FIG. 3B is a perspective view of a stack in a stateafter the elastic member is cut.

FIG. 4A is a front view showing the stack in which the elastic memberinterposed between webs is cut, and FIG. 4B is a front view showing awearing article.

FIGS. 5A and 5B are partial side views showing a circumferentialvelocity of pads.

FIG. 6 is a side layout view showing an apparatus for producing awearing article of Embodiment 2 according to the present invention.

FIG. 7 is a front view showing webs in a state where the elastic memberis placed.

FIG. 8 is a front view showing webs in a state where an absorber isattached.

FIG. 9A shows webs whose both edges are bent, and FIG. 9B shows websfolded into two.

FIGS. 10A to 10F are front views illustrating a method for placing asecond elastic member.

FIGS. 11A to 11C show an example of cutting the elastic member with acutting machine, and FIG. 11D shows another cutting machine.

FIG. 12 shows diapers obtained by cutting the elastic member so that atrim is not generated, and shifting the phase of one web thus cut bysubstantially ½ from the other web.

FIG. 13A is a schematic cross-sectional view illustrating a firstembodiment of the rotation device of the present invention.

FIG. 13B is a side view illustrating the first embodiment of therotation device of the present invention.

FIG. 14A is a schematic cross-sectional view illustrating a secondembodiment of the rotation device of the present invention.

FIG. 14B is a side view illustrating a portion of a fixed pin and groovearrangement for controlling a rotational velocity of a bridging sectionaccording to the second embodiment of the invention.

FIG. 15A is a schematic cross-sectional view illustrating a thirdembodiment of the rotation device of the present invention.

FIG. 15B is a schematic perspective view illustrating an example where aplurality of guides are provided in a concentric manner.

FIG. 15C is a schematic perspective view illustrating another examplewhere a plurality of guides are provided so as to be spaced apart fromeach other in the axial direction of an axis O.

FIG. 16 is a schematic side view illustrating a transfer device.

FIG. 17 is a schematic side view illustrating a folding device.

FIG. 18A is a perspective view illustrating an example of a guide and amoving section.

FIG. 18B is a perspective view illustrating another example of a guideand a moving section.

FIG. 19A is a schematic view illustrating a variation of a foldingdevice.

FIG. 19B is a diagram illustrating plates between two pads being in aspread formation.

FIG. 19C is a diagram illustrating plates being folded into abellows-like shape.

FIG. 19D is an enlarged view illustrating plates between two pads.

FIG. 20 is a schematic diagram illustrating another variation of afolding device.

FIG. 21 is a schematic diagram illustrating another embodiment of afolding device.

FIG. 22 is a perspective view illustrating an example of a top sheet.

FIG. 23 is a perspective view illustrating an example of a top sheetbefore cutting.

FIG. 24 is a perspective view illustrating another example of a topsheet before cutting.

FIG. 25 is a diagram illustrating a portion of another example of abellows-shaped folding device.

FIG. 26A is a diagram illustrating an elastic member being introduced soas to extend across a slack portion that has been obtained through a“Z-shaped folding process”.

FIG. 26B is a diagram illustrating a web after cutting off the elasticmember and removing the slack.

FIG. 27 is a diagram illustrating an example of a device forintermittently introducing an elastic member between a first web thathas been subjected to a “Z-shaped folding process” and a second web.

FIG. 28 is a diagram illustrating an example of a pants-shaped diaper,which is a disposable worn article, being spread out.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, the present invention will be described by way ofillustrative embodiments with reference to the drawings.

Embodiment 1

FIGS. 1 to 5A-B show Embodiment 1.

An apparatus for producing a wearing article shown in FIG. 1 is capableof providing a web with looseness and intermittently placing an elasticmember on at least a part of the web. For example, the apparatus forproducing a wearing article includes a rotation apparatus 1 capable ofproviding a second web W2 with looseness and a second roller 12 capableof placing an elastic member F on portions of the second web W2 otherthan those which are loose. When the elastic member F extending across aloose portion of the second web W2 is cut with at least one of a laser,an industrial light, a blade, and scissors, the apparatus canintermittently place the elastic member F on the second web W2. Thisintermittent placement is mainly caused by the looseness of the secondweb W2. Hereinafter, the configuration and operation of the rotationapparatus 1, the second roller 12, and the like will be described.

In FIG. 1, a supply apparatus 3 of the elastic member F supplies theelastic member F to the surface of a first roller 11. The elastic memberF on the first roller 11 is fed to the second roller 12. Acircumferential velocity V2 of the second roller 12 is set to be largerthan a circumferential velocity V1 of the first roller 11. Therefore,the elastic member F is stretched between the first roller 11 and thesecond roller 12.

The second roller 12 is supplied with a first web W1. The second roller12 transports the first web W1 while sucking the first web W1 by vacuumsuction or the like. On the surface of the second roller 12, forexample, a number of suction holes 12 a for sucking the first web W1 maybe provided. After the first web W1 is sucked to be held on the surfaceof the second roller 12 by vacuum suction or the like, the first web W1is divided into a predetermined size with a web cutter 2. In thisdivision, the first web W1 may be cut or half-cut to a predeterminedlength in a transport direction. In the case where the first web W1 ishalf-cut, the first web W1 may be cut to a predetermined length togetherwith the elastic member F in a subsequent step or cut in a predeterminedlength when an interval of pads is increased. After this division, theelastic member F is placed so as to spread across the surface of therespective first webs W1. In the case where the elastic member F is madeof thread rubber or flat rubber, an adhesive is applied to at least oneof the elastic member F, the first web W1, and the second web.

It may also be possible that after the elastic member F is placed on thefirst web W1, the elastic member F is cut together with the first webW1. Furthermore, in the case where the elastic member F is made ofhot-melt resin, molten resin discharged from the supply apparatus 3 iscooled by the first roller 11. The molten resin may be cooled with coolwater. Furthermore, the first roller 11 may be a porous roller. In thecase where the first roller 11 is a porous roller, the first roller 11may be configured so that air is discharged from the inside of the firstroller 11 through holes. Due to the air, the hot-melt resin becomesunlikely to adhere to the roller. When the air is discharged from theporous body, the volume of the air is increased to cool the roller.Thus, the hot-melt resin can be cooled. The porous roller may be formedby sintering stainless ball or the like.

Furthermore, it may also be possible that the first roller 11 isprovided with grooves or the like, whereby resin is molded. For example,mesh-shaped (for example, lattice-shaped) grooves are formed on thefirst roller 11, and hot-melt resin is applied to the grooves of thefirst roller 11 with a coater or the like, whereby a mesh-shaped elasticmember is formed.

When hot-melt resin having a softening point lower than that of Lycra®is used as the elastic member, the subsequent cutting step becomeseasier, compared with the case of using Lycra®.

The hot-melt resin may be a kneaded composition and may comprise athermoplastic resin, tackifier, viscosity adjuster, antioxidant, heatstabilizer, ultraviolet radiation absorbent, bulking agent, elasticizer,and the like. The thermoplastic resin may include elastomers such asolefins {EVA (ethylene-vinyl acetate copolymer), APAO(amorphous-poly-α-olefin)}, rubbers {SIS (styrene-isoprene-styrenecopolymer), SBS (styrene-butadiene-styrene copolymer), SEBS(styrene-ethylene-butadiene-styrene copolymer), SEPS(styrene-ethylene-propylene-styrene copolymer)}, polyamides andpolyesters. The thermoplastic resin may be a single elastomer or a blendof more than one elastomer.

The rotation apparatus 1 for folding is placed in the vicinity of thesecond roller 12. The rotation apparatus 1 has a plurality of pads 9capable of sucking the second web W2 and transporting it. On the surfaceof a pad 9 _(i), suction holes 10 for sucking the second web W2 areprovided. The rotation apparatus 1 continuously transports the secondweb W2, and is in contact with the surface of the second roller 12 viathe first web W1, the elastic member F, and the second web W2 at acontact point O (predetermined position). Thereafter, the following mayalso be possible: an additional roller and the pad 9 _(i) sandwich thefirst web W1, the elastic member F, and the second web W2 placed on thepad 9 _(i), whereby the contact therebetween is enhanced.

The elastic member F is cut after being interposed between the first webW1 and the second web W2. The elastic member F is fixed between the websW1 and W2, so that the elastic member F shrinks less, compared with thecase where the elastic member F is placed on one web.

The rotation apparatus 1 receives the second web W2 at a circumferentialvelocity V11 at a receiving position RP. At a point “A” where the pad 9_(i) receives the second web W2, the circumferential velocity of the padis V11. FIG. 5A is a side view showing the enlarged vicinity of thepoint “A” of FIG. 1. During a period from a time when at least a part ofthe pad 9 _(i+1) shown in FIG. 5A receives the second web W2 to a timewhen at least a part of the pad 9 _(i) adjacent to the pad 9 _(i+1)receives the second web W2, the pad 9 _(i+1) moves at a substantiallyconstant circumferential velocity V11. The reason for this is to preventthe second web W2 from being damaged.

Each pad 9 _(i) of the rotation apparatus 1 is rotated at the receivingposition RP at the circumferential velocity V11, and decelerates to acircumferential velocity V21 before reaching the contact point O (wherethe distance between the pad 9 _(i) and the pad 9 _(i+1) becomesminimum). Therefore, the interval between the pad 9 _(i) and the pad 9_(i+1) becomes narrow before the pad 9 _(i) moves from the receivingposition RP to the contact point O. This causes the second web W2 tobecome loose between the pad 9 _(i) and the pad 9 _(i+1), whereby aloose portion Wa is formed.

The pad 9 _(i) comes into contact with the second roller 12 via thesecond web W2 and the like at the circumferential velocity V21 (V11>V21)at the contact point O shown in FIG. 1. The first web W1 is transferredfrom the second roller 12 at the circumferential velocity V2. Thecircumferential velocity V21 of the pad 9 _(i) is set at a substantiallyconstant velocity equal to or close to the circumferential velocity V2of the second roller 12. That is, while at least the pad 9 _(i) is incontact with the second roller 12 via the second web and the like or atleast the pad 9 _(i) places the first web W1 on the second web W2, thepad 9 _(i) moves at the substantially constant circumferential velocityV21 substantially equal to V2. In other words, during a period from atime when the second web W2 on the pad 9 _(i) starts receiving the firstweb W1 to a time when the second web W2 finishes receiving it, the pad 9_(i) moves the constant circumferential velocity V21 (≈V2). Thedifference in velocity prevents the first web W1 and the second web W2from being shifted from each other, and exactly places the first web W1at a predetermined position of the second web W2.

The circumferential velocity of the pad becomes V31 at a point B wherethe pad releases the second web W2. FIG. 5B is a side view showing theenlarged vicinity of the point B. The pad 9 _(i) moves at asubstantially constant circumferential velocity V31 at least during aperiod from a time slightly before the pad 9 _(i+1) adjacent to the pad9 _(i) releases the second web W2 to a time when the pad 9 _(i) releasesthe second web W2 (FIG. 5B). The reason for this is to minimize thefluctuation in velocity of the released second web W2. For example, inthe case where the circumferential velocity of an embossing roller 5 isV3, the circumferential velocity V31 becomes substantially equal to V3.

When or after the circumferential velocity of the pad 9 _(i) becomesmaximum in the vicinity of the point A in FIG. 5A, the pad 9 _(i)receives the second web W2. If the pad 9 ₁ receives the second web W2before the circumferential velocity of the pad 9 _(i) becomes maximum,the interval between adjacent pads is increased, which may damage thesecond web W2. As the operation of the pad 9 _(i), the pad 9 _(i) maymove at a maximum circumferential velocity, for example, during a periodfrom the point B to the point A. In this case, a region from the point Bto the point A can be dealt with as one region. That is, in the presentembodiment, the circumferential velocity of the pad may becomesubstantially constant at least at two points.

It is preferable that the apparatus is provided with a directing part sothat the loose portion Wa in FIG. 1 becomes loose exactly toward thecenter of the rotation apparatus 1.

The directing part may be, for example, a mechanism for jetting air or amechanism for pushing the loose portion Wa of the web toward the centerof the rotation apparatus 1. Alternatively, the directing part may be amechanism for sucking the web W toward the center of the rotationapparatus 1 by vacuum suction. In the case where the directing part is amechanism for jetting air, one or a plurality of directing parts may beprovided. Furthermore, in the case where the directing part is amechanism for pushing the loose portion Wa, one or a plurality ofdirecting parts may be provided. By providing a plurality of directingparts, the loose portion Wa can be bent exactly toward the center of therotation apparatus 1. In the present embodiment, the loose portion Wamay have a shape dented toward the center of the rotation apparatus 1due to the weight of the second web W2.

Next, a folding operation will be described. When the second web W2 issucked to be held on the surface of the pad 9 ₁ at the receivingposition RP, the second web W2 is transported along the pad 9 ₁ of therotation apparatus 1. When the pad 9 ₁ is rotated from the receivingposition RP to the contact point O, the interval between the pads 9 _(i)is decreased. Because of this, the loose portion Wa is formed in thesecond web W2. Furthermore, the loose portion Wa is folded into two toform a folded portion Wb.

The rotation apparatus for conducting the above-mentioned “folding” isnot limited to the rotation apparatus 1. For example, an apparatusdescribed in Japanese Patent Application No. 2001-545183 A may be used.The present invention is intended to place an elastic memberintermittently on a web. Therefore, the second web W2 is not necessarilyfolded completely. Furthermore, depending upon the shape of the pad 9_(i), the second web W2 may have a loop shape.

The folded second web W2 is attached to be stacked on the first web W1at non-folded portions We before and after the folded portion Wb. Thatis, the elastic member F is not cut until the elastic member F is placedand fixed between the first web W1 and the second web W2. Therefore, thestretched elastic member F hardly shrinks on the second web W2. When thesecond web W2 is stacked on the first web W1, the first web W1 is notplaced on the folded portion Wb folded between the pads 9 _(i) and 9_(i+1) adjacent to each other in the vicinity of the contact point O.When the interval between the pads 9 _(i) and 9 _(i+1) is increased asshown in FIG. 2, only the elastic member F is exposed as shown in FIG.3A.

As shown in FIG. 1, during β from a time when the first web W1 isattached to the second web W2 to a time when the first web W1 isreceived, suction of air through the suction holes 12 a of the secondroller 12 may be stopped or air may be discharged through the suctionholes 12 a. The purpose of this is to attach the first web W1 to thesecond web W2 smoothly.

The exposed elastic member F in FIG. 3A is cut with a cutter. In thecase where the elastic member F can be cut with a light cutter, a lightcutter 4 shown in FIG. 2 is used. The light cutter 4 has a rotatablecover, and a slit 42 is formed at a part of the cover. The cover 41 withthe slit 42 is rotated, whereby infrared rays are radiatedintermittently from a light source 40 to the elastic member F to cut itat a predetermined pitch. When the elastic member F is cut with thelight cutter 4, there is no possibility that the webs W1 and W2 aredamaged by heat from the light cutter 4, since the elastic member F isaway from the loose portion Wa. The elastic member F may be cut with apressure, heat, UV-rays, a laser or at least two of them. Furthermore,the elastic member F may be cut with an ultrasonic wave.

Hereinafter, an example of cutting the elastic member F with a cutterwill be described. FIG. 11A is a view showing a cutting machine 43 thatis an example of a cutter. The cutting machine 43 has a rotatable roller44 and at least one of blade 45 placed at the roller 44. The distancebetween the rotation center of the roller 44 and the center of therotation apparatus 1 is hardly changed. The blade 45 can cut the elasticmember F positioned on the loose portion Wa between the pads 9 _(i) andthe pad 9 _(i+1), when the roller 44 is rotated. The rotation of theroller 44 is changed in accordance with the rotation of at least one ofthe pad 9 _(i) and the pad 9 _(i+1). The blade (s) 45 may have a linearshape (FIG. 11B) or may be in a jagged shape (FIG. 11C). Furthermore,the blade 45 may be reciprocated in the direction of the rotation axis.

FIG. 11D shows another cutting machine 46. The cutting machine 46includes a rotatable large roller 47, a rotatable small roller 48attached to the large roller 47, and a blade 49 placed at the smallroller 48. The blade 49 of the cutting machine 46 can cut the elasticmember F positioned on the loose portion Wa between the pad 9 _(i) andthe pad 9 _(i+1), when the large roller 47 and the small roller 48 arerotated. The rotations of the large roller 47 and the small roller 48are changed in accordance with the rotation of at least one of the pad 9_(i) and the pad 9 _(i+1). As shown in FIG. 11D, when the blade 49reaches the bottom dead point, the tip end of the blade 49 is preferablydirected to the center of the rotation apparatus 1. Furthermore, in thesame way as in the blade 45, the blade 49 may have a shape as shown inFIG. 11B or 11C, and may be reciprocated in the direction of therotation axis of the large roller 47 or the small roller 48.

The small roller 48 of the cutting machine 46 may have a plurality ofblades 49 as shown in FIG. 11E. The blades 49 may be reciprocated in thedirection of the rotation axis to cut the elastic member.

The rotation apparatus 1 may be provided with scissors instead of thecutting machine. After the second web W2 is stacked on the first web W1,and the interval between the pad 9 _(i) and the pad 9 _(i+1) is slightlyincreased, the scissors may enter between the pad 9 _(i) and the pad 9_(i+1) to cut the elastic member stretched between the pad 9 _(i) andthe pad 9 _(i+1). The scissors may enter between the pad 9 _(i) and thepad 9 _(i+1) in accordance with the rotation of at least one of the pad9 _(i) and the pad 9 _(i+1). In order for the scissors to perform suchan operation, at least one of a cam mechanism and a link mechanism maybe used.

In FIG. 1, the circumferential velocity of the pad 9 ₃ becomes avelocity V31 (V31>V21) at a releasing position SP where the pad 9 ₃releases the second web W2. Therefore, the interval between the pads 9 ₃and 9 ₄ is increased from the contact point O to the releasing positionSP. Therefore, the tension stress and elongation of the elastic member Fare increased from the contact point O to the releasing position SP.When the elastic member F is cut with the light cutter 4 in this state,cutting becomes easy. At the releasing position SP, a stack N1 in FIG.3B, in which the webs W1 and W2 and the elastic member F are stacked, isin the state before the folded portion Wb is folded.

Herein, during a from the releasing position SP to the receivingposition RP, suction through the suction holes 10 may be stopped, andair may be discharged through the suction holes 10. The purpose of thisis to smoothly transfer the stack N1 in a downstream direction.

As shown in FIG. 1, an embossing roller 5 may be provided downstreamfrom the releasing position SP. The stack N1 in FIG. 3B is sent to theembossing roller 5. A plurality of convex portions 51 are arranged onthe embossing roller 5, and at least the elastic member F of the stackN1 is cut with the convex portions 51. Because of this, as shown in FIG.4A, the stack N1 is obtained in which the shrinking force of a part ofthe elastic member F interposed between the first and second webs W1 andW2 is suppressed. An adhesive is not basically applied to a portion CPwhere the shrinking force of the elastic member F is suppressed by theembossing roller 5. The reason for this is to protect the shrinking ofthe elastic member F. However, in order to control the shrinking of theelastic member F, some adhesive weaker than usual may be applied.

A portion represented by a solid line in FIG. 4B shows an example of adisposable diaper produced by the production method of the presentinvention. In the stack N1, at least a part of an absorber C is fixed atthe portion Wb of the stack N1 where the elastic member F is not placed.The other end of the absorber C is connected to another stack N2represented by a broken line. The absorber C is folded into two, and theportion CP of the stack N1 comes into contact with a correspondingportion of another stack N2, whereby continuous disposable diapers canbe produced. Another stack N2 may have the same configuration as that ofthe stack N1. Furthermore, in the case where the absorber C is foldedinto two, and the portion CP of the stack N1 comes into contact with thecorresponding portion of another stack N2, whereby the stacks N1 and N2are stretched in a flow direction, even if the elastic member F isplaced at the portion CP, the above connection can be conducted.

Furthermore, the following may also be possible: when the elastic memberF is cut so that a trim is not generated as shown in FIG. 12, and thephase of one web thus cut is shifted by substantially ½ from the otherweb, whereby the web W2 shown in FIG. 4B is formed. As a method forshifting a phase, one web may be allowed to pass through a dummy rollerto cause a delay from the other web.

Embodiment 2

Next, Embodiment 2 will be described. A production apparatus shown inFIG. 6 is capable of placing at least three kinds of elastic members F1to F3 for a leg gathering on a wearing article, as shown in FIG. 9A.

(1) Arrangement State of Elastic Members:

First, as shown in FIG. 7, the configuration and operation of thepresent apparatus for obtaining an arrangement state of elastic members,in which first and second elastic members F1 and F2 are placed on websW1 and W2, will be briefly described.

The present apparatus includes a first roller 11 for placing a firstelastic member 1 for a waist gathering and a guide unit 23 for placing asecond elastic member 2 for a leg gathering. The guide unit 23 iscapable of arranging the second elastic member F2 for a leg gathering ina curved shape or a linear shape by being reciprocated in the axisdirection of a second roller 12 with, for example, a cam or a servomotor. U.S. patent application Ser. No. 10/095,959 discloses an exampleof the guide unit 23. The second elastic member F2 may be cutmechanically with scissors, a blade, or the like provided at the roller.FIGS. 11A to 11D show examples of a cutter. The first elastic member F1may not be a thermoplastic elastic member. In this case, the firstelastic member F1 can be cut with scissors, a blade, or the like in thesame way as in the second elastic member F2. Furthermore, the first andsecond elastic members F1 and F2 may be cut with the same scissors,blade, or the like. In the steps until here in Embodiment 2, the otherconfiguration is the same as that of Embodiment 1. Like parts aredenoted with like reference numerals, and the detailed description anddrawings are omitted here.

After being interposed and fixed between the first and second webs W1and W2, the first and second elastic members F1 and F2 are cut to bearranged as shown in FIG. 7.

In some disposable wearing articles, an elastic member for a leggathering is placed on a crotch portion. Therefore, such a portioncontrasts to cause an unsatisfactory feeling during wearing. In order toavoid this, the elastic member on the crotch portion is cut so as toshrink, whereby the elastic member on the crotch portion can be madeshort to some degree. However, it is impossible to completely eliminatethe elastic member on the crotch portion, so that an unsatisfactoryfeeling may still remain.

In contrast, when the second elastic member F2 for a leg gathering isplaced as shown in FIGS. 10A, 10C, and 10E, the second elastic member F2can be eliminated from the crotch portion G. FIGS. 10A, 10C, and 10Eshow the second elastic member F2 interposed between the first web W1and the second web W2 on adjacent pads 9, wherein a part of the web W2is interposed between the adjacent pads 9.

For example, as shown in FIGS. 10A and 10 c, a folded portion Wb isformed on the crotch portion G of the first web W1, and the secondelastic member F2 is placed on non-folded portions Wc. Thereafter, thesecond elastic member F2 striding across the adjacent pads 9 is cut. Asa result, the second elastic member F2 is not placed on the crotchportion G, as shown in FIGS. 10B and 10D.

Furthermore, as shown in FIG. 10 e, when a non-coated portion Df with noadhesive applied thereto is provided in the non-folded portion Wcadjacent to the vicinity of the folded portion Wb, after the secondelastic member F2 is cut, a portion of the second elastic member F2 thatis not sufficiently attached to the non-folded portion Wc shrinks (FIG.10F). Full-circle pants may be produced by such adjustment of anadhesive. Some adhesive may be applied to the non-coated portion Df. Inthis case, the second elastic member F2 shrinks slowly without beingfixed to the non-folded portion Wc, and finally, the second elasticmember F2 can be eliminated from the crotch portion G.

The adhesive only needs to be applied to a portion where the secondelastic member F2 is placed. As a coating method, an adhesive may beapplied in an annual shape to at least one of the first and second websW1 and W2 with a coater or the like. Furthermore, guns with a pluralityof valves are placed in a direction across the first web W1 so thatopening/closing of the valve may be controlled by the flow speed of atleast one of the first web W1 and the second web W2 and the coatingshape. In the case of using such guns, an adhesive can be applied inarbitrary regions partitioned in a matrix.

(2) Attachment State of an Absorber:

An absorber C is arranged and attached to the webs W1 and W2 in theabove-mentioned arrangement state of the elastic members by a turnapparatus 30. Thereafter, a third elastic member F3 for a waistgathering is placed to form an attachment state of an absorber as shownin FIG. 8.

The turn apparatus 30 is provided with a plurality of suction pads 30 paround a drum (not shown). The suction pads 30 p are rotated in an arrowdirection while changing the posture of the absorber C by 90° byturning. As the turn apparatus 30, for example, an apparatus asdisclosed by International Publication No. WO 01/44086 or U.S. PatentApplication Publication No. US 2002/0103468 may be used, as is describedin more detail below.

(3) Both-Edge Folded State:

Thereafter, the webs W1 and W2 with the absorber attached thereto havetheir folding portions E on both edges folded inward at a position oftwo-dot dash lines L₂ shown in FIG. 8 by a folding apparatus 31. Afterboth edges of the webs W1 and W2 are folded, a leg hole Lh is cut outwith a leg hole cutter 32 (FIG. 6), whereby a both-edge folded stateshown in FIG. 9A is formed. The leg hole cutter 32 may be placedupstream from the turn apparatus 30. In such a configuration, it alsobecomes possible to produce a disposable wearing article in which a partof the absorber C extends out to the leg hole Lh portion.

(4) Two-Folded State:

After folding, the webs W1 and W2 are folded into two at a folding lineB by a two-folding apparatus 33, whereby the webs W1 and W2 are foldedinto two as shown in FIG. 9B. As the two-folding apparatus 33, forexample, an apparatus described in U.S. Pat. No. 3,828,367, U.S. Pat.No. 5,711,832, or U.S. patent application Ser. No. 10/147,644 may beused.

Thereafter, the webs W1 and W2 folded into two have both edges L sealed(e.g., heat-sealed or sonic-sealed), as shown in FIG. 9B. Thereafter, acutting portion D represented by a two-dot dash line is cut to form anindividual disposable wearing article, e.g., pants P.

The present apparatus may form pants P from the webs W1 and W2(hereinafter, referred to as a “stacked web W”) folded into two, using adecelerating drum 34, a main drum 37, a seal roller 35, and a cutterroller 36.

Decelerating Drum 34:

As described above, although the web W has an elastic member, the web Wis moved in a stretched state so that placement of an absorber at apredetermined position, formation of a leg hole, and other processingcan be performed easily. However, in order to seal the web W and cut aseal portion, the position of the edge L only needs to be determined.This is because the state of the other portions of the web W does notinfluence a sealing step and a cutting step. Furthermore, in the sealingstep, it is preferable that a flow speed of the web W is lower so as toobtain a sufficient time for melting a part of the web W and the like.The decelerating drum can decrease the flow speed of the web W so as toobtain a sufficient time for melting the part of the web W and the like.As the decelerating drum 34, an apparatus described in JP 63-317576 A,International Publication No. WO 01/44086, or U.S. Patent ApplicationPublication No. 2002/0103468 may be used.

The decelerating drum 34 is provided with a plurality of pads 34 protating in a transport direction of the stacked web W around a drum(not shown). The decelerating drum 34 receives at least an edge L at areceiving position RP from the two-folding apparatus 33 placed upstreamtherefrom, and holds it. The other portions of the web W are positionedbetween adjacent pads 34 p. The edge L is transported to a releasingposition SP, and thereafter, the edge L is supplied to the main drum 37placed downstream therefrom at the releasing position SP. While the pad34 p moves from the receiving position RP to the releasing position SP,the interval between the adjacent pads 34 p is changed to be narrow.

The pad 34 p is capable of receiving the edge L in a stretched state atthe receiving position RP, and keeping holding the edge L shown in FIG.9B. For example, the edge L may be held by sucking the edge L, pressingthe edge L with a hook, or fixing the edge L with a pin placed at thepad 34 p. On the other hand, the interval between the adjacent pads 34p, which has been increased at the receiving position RP, is decreasedbefore the releasing position SP, and a shrinking portion S excludingthe edge L shrinks in a transport direction X. In order to allow theedge L to be exactly held, the shrinking force of the elastic memberpositioned at the edge L may be weakened by an embossing roller 38. Forexample, the embossing roller 38 can cut the elastic member to apredetermined length or change the elastic configuration of the elasticmember by using at least one of heat and pressure. As the embossingroller 38, for example, an apparatus described in U.S. PatentApplication Publication No. 2002/0103468 may be used. The embossingroller 38 is placed in a region from the rotation apparatus 1 to thetwo-folding apparatus 33.

Main Drum 37:

The main drum 37 receives the web W in a mixed state where the stretchededge L and the shrinking portion S that has shrunk are presentalternately from the decelerating drum 34. The main drum 37 transportsthe web W in such a mixed state. In order to keep the mixed state, themain drum 37 may be provided with, for example, a plurality of suctionholes to suck air through the suction holes so as to suck the web W.

Seal Roller 35:

The seal roller 35 can conduct heat-sealing by heating and pressing theedge L (FIG. 9B) of the web W. More specifically, the web W is pressedby being interposed between the seal roller 35 and the main drum 37, andheated by the seal roller 35. The seal roller 35 may be provided with,for example, a heater so as to heat-seal the edge L. Furthermore, theseal roller 35 may have a horn to conduct sonic-sealing. The web Wsubjected to the above-mentioned heat-sealing is cut to individual pantsP by a cutter roller 36 placed downstream therefrom.

Formation Operation of Pants P:

Next, an operation of forming pants P from the stacked web W will bedescribed. The decelerating drum 34 continuously receives the web W ontoeach pad 34 p under the condition that the web W is stretched in a flowdirection. Herein, the pad 34 p holds the edge L (FIG. 9B) of the web Win a stretched state.

After receiving the web W, the pad 34 p having received the web W hasits circumferential velocity decreased, whereby the interval between theadjacent pads 34 p becomes narrow. Therefore, a portion S other than theedge L of the web W shown in FIG. 9B shrinks in a transport direction Xto form the shrinking portion S. On the other hand, the edge L is heldin a stretched state.

Thereafter, the main drum 37 receives the web W from the deceleratingdrum 34. At this time, the main drum 37 receives the web W in a mixedstate where the edge L in a stretched state and the shrinking portion Sthat has shrunk are present alternately. The main drum 37 transports theweb Win a downstream direction while keeping the mixed state. Duringtransportation by the main drum 37, the seal roller 35 presses and heatsthe edge L of the web W on the main drum 37. Herein, a part of the web Wshrinks, so that the transport velocity of the web becomes low. Sealingcan be conducted exactly, as the transport velocity of the web W is low.

Thereafter, the web W is cut to individual pieces with a cutter roller36 to form pants P.

As described above, according to the present invention, after beinginterposed and fixed between a first web and a second web, an elasticmember is cut. Therefore, the stretched elastic member hardly shrinks onthe second web, whereby an expected gathering is obtained.

Furthermore, according to the present invention, the elastic member iscut between adjacent first webs. Therefore, the second web and anabsorber do not become stiff between the first webs.

Furthermore, a plurality of first webs are placed on a second web underthe condition where they are away from each other. Therefore, the firstweb is not stacked on a portion where a gathering of the elastic memberis not formed, so that such a portion becomes thin and allows air topass therethrough. As a result, a user wearing such an article is notlikely to feel stuffy.

Furthermore, the elastic member is cut between the first webs and at aloose portion of the second web. Therefore, only the elastic member canbe cut without damaging the web.

If a pad that makes the second web loose is allowed to transport thesecond web at a substantially constant velocity during a predeterminedperiod from a time when the pad starts receiving the first web to a timewhen the pad finishes receiving it, the first web can be transferred toa predetermined posit ion of the second web exactly.

Furthermore, if the elastic member is cut under the condition that thetension stress of the elastic member is increased, the elastic membercan be cut easily with infrared rays or the like.

Furthermore, while the web is transported under the condition that anedge (where the web is stretched) and a shrinking portion (where the webshrinks) are present alternately in a transport direction, a heatingtime for heating the edge becomes long. Therefore, the transportvelocity of the web can be increased without impairing the exactness ofheat-sealing.

Referring now to FIGS. 13A-28, further detail regarding the rotationapparatus or device will be described as originally set forth in U.S.Patent Application Publication No. US 2002/0103468.

FIG. 13A and FIG. 13B illustrate an embodiment of the present invention.

A rotation device 1 includes a rotation section B, a guide 3′ and aplurality of moving sections 4 ₁ to 4 _(n). In the present embodiment,the rotation device 1 also includes a driving section 2′.

The driving section 2′ inputs a rotational force to the moving sections4 _(i). A rotational force from a rotational power source such as amotor is transmitted to the driving section 2′ via a power transmissionportion 5′ and a shaft 20, so that the driving section 2′ rotates aboutan axis O at a constant velocity, for example. The driving section 2′ isaxially and rotatably supported by a drum 6 via a bearing B1. The axis Oof the driving section 2′ is eccentric to an axis C of the drum 6. Dueto such an eccentric structure, it is possible to, for example,periodically change the velocity of each moving section 4 _(i) while thedriving section 2′ rotates.

A guide 3′ is attached to the drum 6 via the rotation section B′ such asa ball bearing and a rotation ring 50. In the rotation device 1illustrated in FIG. 13A, two or more endless guides 3′ are providedspaced apart from each other in the axial direction of the drum 6. Asshown in FIG. 13B, a plurality of moving sections 4 ₁ to 4 _(i) areattached to each guide 3′ so that the moving sections 4 ₁ to 4 _(i) aremovable in the circumferential direction of the guide 3′. Therefore,each moving section 4 _(i) rotates around the drum 6 along with theguide 3′ while additionally moving relative to the guide 3′ around thedrum 6 along the guide 3′.

For the guide 3′ and the moving section 4 _(i), an R Guide manufacturedby THK® Co., Ltd., as illustrated in FIG. 18A, or a Gonio Waymanufactured by Nippon Bearing Co., Ltd., may suitably be employed.Preferably, a rolling element such as a ball or a wheel is insertedbetween the guide 3′ and the moving section 4 _(i). Each guide 3′ may bea number of rails or grooves attached together in the circumferentialdirection of the rotation section B′. Basically, it is preferred thatthe reciprocating movement is a rolling movement of a bearing, or thelike, but may alternatively be a sliding movement.

In FIG. 13A, a bridging section 7 _(i) is provided so as to extendbetween each pair of moving sections 4 _(i) that are spaced apart fromeach other in the axial direction of the drum 6. One end of an arm 70_(i) is fixed to the bridging section 7 _(i), and a link 8 i isrotatably attached to the other end of the arm 70 _(i).

In the present embodiment, a controller, being capable of moving themoving sections 4 i at a programmed velocity, is provided by the link 8i in combination with the eccentricity between the axes C and O.Alternatively, the controller may be provided by any other linkmechanism, or a controller described in PCT International PublicationWO01/44086, for example, may be used.

One end of each link 8 i is rotatably attached to the driving section 2via a bearing B2 and a fixed pin 8 a, and the other end of each link 8 iis rotatably attached to the arm 70 _(i) via a bearing B3 and a rotationpin 8 b. As the driving section 2 rotates at a substantially constantvelocity, the fixed pin 8 a rotates, together with the driving section2, at a substantially constant angular velocity, while the rotation pin8 b rotates around the fixed pin 8 a. Thus, the angular velocity of therotation pin 8 b changes depending on the rotation angle of the rotationpin 8 b. Therefore, the bridging section 7 _(i) integral with therotation pin 8 b rotates around the drum 6 while changing the interval(pitch) with respect to an adjacent bridging section 7 _(i), asillustrated in FIG. 13B.

Specifically, each bridging section 7 i rotates at a relatively lowvelocity while it rotates from the position of the bridging section 7_(n) to that of the bridging section 7 ₂ of FIG. 13B, whereas thebridging section 7 _(i) rotates at a higher velocity while it rotatesfrom the position of the bridging section 7 ₂ to that of the bridgingsection 7. Therefore, the spacing interval (pitch) between adjacentbridging sections 7 _(i) changes along with the rotation of the bridgingsections 7 _(i).

FIG. 14A and FIG. 14B illustrate another embodiment of the rotationdevice 1.

In the present embodiment, the rotation ring 50 is coupled to eachrotation section B′, and an attachment section 75 _(i), through which apad to be described later is inserted, is provided in a generallycentral portion of each bridging section 7 _(i). The attachment section75 _(i) may be a space in the form of a through hole, a notch, adepression, etc.

Moreover, in the present embodiment, a groove 8A_(i) elongated in theradial direction of the drum 6 is provided, instead of the link 8 i, atan end of each bridging section 7 _(i). The groove 8A₁ is provided withthe fixed pin 8 a illustrated in FIG. 14B so that the fixed pin 8 a isslidable in the radial direction. Therefore, the rotational velocity ofthe bridging section 7 _(i) changes as in the previous embodiment.

In the rotation device of FIG. 14A and FIG. 14B, the velocity of thebridging section 7 _(i) may be controlled by a link as illustrated inFIG. 13, or alternatively by any other controller mechanism as describedabove.

FIG. 15A to FIG. 15C schematically illustrate another embodiment of therotation device of the present invention.

The rotation device 1 illustrated in FIG. 15A includes an endless guide3′, a plurality of moving sections 4 _(i) moving along the guide 3′, andthe rotation section B. The rotation section B′ allows the guide 3′ torotate about the axis of the rotation section B′.

The plurality of moving sections 4 _(np) are arranged in the rotationallowance direction of the section B′ (i.e., the direction in which therotation section B′ allows the guide 3′ to rotate). Each moving section4 _(i) can move away from or toward an adjacent moving section 4 _(i),and can reciprocate along the guide 3′ in the direction of rotation ofthe rotation section B′ or in the opposite direction. If thereciprocating movement is done over a particular region of the rotationsection B′, the guide 3′ may not need to be endless. Specifically, aplurality of arc-shaped guides 3′ may be arranged about the axis O ofthe rotation section B′ so as to be spaced apart from one another in therotation allowance direction of the rotation section B, surrounding theaxis O. In such a case, each of the plurality of guides 3′ includes atleast one moving section that is movable in the direction of rotation ofthe rotation member or in the opposite direction.

The guide 3′ of FIG. 15A is rotated at a predetermined rotationalvelocity about the axis O by a rotational force applying member (e.g., amotor or a power transmission device), which is not shown in the figure.The annular guide 3′ is arranged at a predetermined position withrespect to the rotation section B′. A plurality of moving sections 4 ₁to 4 _(i) are movably attached to the guide 3′.

Each moving section 4 _(i) can move along the guide 3′ along with therotation of the rotation section B′.

The interval between a pair of adjacent moving sections (e.g., 4 ₂ and 4₃) changes depending on the rotational position. A predeterminedcontroller as described above may be employed to accurately control suchan interval. However, a certain level of control can be provided by, forexample, the gravitational acceleration acting on the moving sections 4_(i). Alternatively, a motor may be provided for each moving section 4 ifor driving the moving section 4 _(i) along the guide 3′ so that themoving section 4 i rotates at an instantaneous velocity according to arotational angle .theta..sub.i.

In this embodiment, the rotation section B′ may be optional. Therotation device 1 includes the endless guide 3′, and a plurality ofmoving sections 4 _(i) that move while being guided by the guide 3′. Therotation device 1 in which the guide 3′ is provided with a plurality ofmoving sections 4 _(i) may have a poor friction resistance as comparedwith one using ball bearings, but such a rotation device 1 can belighter in weight than rotation devices in the prior art.

FIG. 16 illustrates an example of a method for transferring a wornarticle using the rotation device 1.

The rotation device 1 includes pads 9 _(i) each attracting an article Nand allowing the article N to be transferred. In the rotation device 1illustrated in FIG. 13A and FIG. 13B, each pad 9 _(i) may be provided inthe bridging section, or the bridging section may serve as a pad (i.e.,the bridging section itself may be used as a pad). In the rotationdevice 1 illustrated in FIG. 14A and FIG. 14B, each pad 9 _(i) may befit into the attachment section 75 _(i) of the bridging section so thatthe pad 9 _(i) can rotate (e.g., about the direction normal to the drum6), or the bridging section may serve as a pad. In the rotation device 1illustrated in FIG. 15A to FIG. 15C, each pad 9 _(i) may be provided inthe moving section.

Each pad 9 _(i) of FIG. 16 includes a plurality of suction holes forattracting the article N, and the suction holes are placed under anegative pressure to attract the article N while the pad is moving fromthe position of the pad 9 ₁ (where the article N is received from afirst conveyer C1) to the position of the pad 9 ₃ (where the article Nis handed over to a second conveyer C2). The pad 9 _(i) mayalternatively attract the article N by using an electrostatic charge, orthe like.

The first conveyer C1 is provided upstream of the rotation device 1, andthe second conveyer C2 is provided downstream of the rotation device 1.The first conveyer C1 transfers the articles N to the rotation device 1at an interval D1.

For example, each pad 9 _(i) rotates at a circumferential velocity V1that is about the same as that of the first conveyer C1 from when itcomes near a pickup position RP until it passes the pickup position RP,and rotates at a circumferential velocity V2 that is about the same asthat of the second conveyer C2 from when it comes near a hand-overposition SP until it passes the hand-over position SP. In the rotationdevice 1 illustrated in FIG. 16, i.e., in a case where it is desired toincrease the interval between pads, the relationship between thecircumferential velocities is V2>V1. However, the relationship betweenthe circumferential velocities is V2<V1 in a case where it is desired toshorten the interval between pads. The circumferential velocity of thesecond conveyer is about V2.

As the article N₁ is transferred by the first conveyer C1 to the pickupposition RP, article N₁ is attracted onto the pad 9 ₁ and the pad 9 ₁receives the article N₁ at the pickup position RP. Then, the pad 9 ₁rotates toward the hand-over position SP, where the pad 9 ₃ releases thearticle N₃, while gradually increasing the velocity thereof. At thehand-over position SP, the pad 9 ₃ stops attracting the article N₃,whereby the second conveyer C2 can easily attract and receive thearticle N₃.

In a case where a portion of the pad 9 _(i) is rotatably fit into theattachment section of the bridging section, the pad 9 _(i) may rotateabout a normal direction CL by a predetermined angle (e.g., 90°) tochange the orientation of the article N_(i) while the pad 9 _(i) movesfrom the pickup position RP to the hand-over position SP. The articleN_(i) may be a final or intermediate product of a worn article such as anapkin, a disposable diaper, disposable pants or a bandage, or may be asingle-layer or multilayer sheet of woven fabric, non-woven fabric, aliquid permeable sheet or a liquid impermeable sheet. The intermediateproduct may be an absorbent or absorbents arranged over a web.

FIG. 17 illustrates an example of a method for folding a web W using therotation device 1.

In the figure, each bridging section 7 _(i) includes the pad 9 _(i) forattracting the web W so that the web W can be transferred. The pad 9_(i) attracts the web W while it is moving from the position of the pad9 ₁ (where the web W is received) to the position of the pad 9 ₃ (wherea folded web is transferred) in FIG. 17.

The rotation device 1 forms a wheel for continuously transferring theweb W, and is in contact with the surface of a belt 31′ of a conveyer30′ via the web W.

The rotation device 1 picks up the web W traveling at a first velocityV11, and hands it over to the conveyer 30′ traveling at a secondvelocity V21 (V11>V21). The belt 31′ of the conveyer 30′ basicallytransfers the web W at the circumferential velocity V21. Specifically,each pad 9 _(i) rotates at the circumferential velocity V11 at theposition of the pad 9 ₁ (where the web W is received), and slows down tothe circumferential velocity V21 by the time it reaches the position ofthe pad 9 ₃ (where a folded web is transferred). Therefore, the intervalbetween adjacent pads 9 _(i) is shortened while the pads 9 _(i) movefrom the pickup position RP to the hand-over position SP, therebyslackening the web W between the pads 9 _(i) to form a slack portion W1.

Next, the operation will be described. The web W is supplied by beingattracted onto the surface of the pad 9 ₁ at the pickup position RP, andthen transferred along the pads 9 _(i) of the rotation device 1. Whilethe rotation section B′ rotates in the direction of an arrow Vh, the pad9 ₁ moves along the guide 3′ and in the opposite direction Vs, therebyreducing the interval between the pads 9 _(i). The direction Vs isdefined with respect to the guide 3′. Therefore, a folded portion W2 isformed in the web W. After the formation of the folded portion W2, thepad 9 ₄ stops attracting the web W, whereby the web W including foldedportions W2 at a predetermined pitch is transferred onto the conveyer30′, thereby performing a so-called “Z-shaped folding process”.

The rotation device for performing the Z-shaped folding process may notbe the rotation device 1 described above, but may alternatively be, forexample, a device described in PCT International Publication WO01/44086,or a device using any other link mechanism.

Another example of a folding device for performing the Z-shaped foldingprocess is illustrated in FIG. 19A.

In FIG. 19A a rotation device 1A includes a plurality of pads 9 _(i). Atleast one suction hole 10 for attracting the web W is provided in thesurface of each pad 9 _(i). The velocity of the pad 9 _(i) is the sameas that of the web W at the pickup position RP. However, at thehand-over position SP, the velocity is lower than that at the pickupposition RP. Therefore, a slack portion W1 is formed in the web W.Preferably, the folding device includes a directioning section 12′ so asto ensure that the slack portion W1 is folded in toward the center ofthe rotation device 1A.

The directioning section 12′ may be, for example, a mechanism that blowsout a stream of air, a mechanism that thrusts the slack portion W1 ofthe web toward the center of the rotation device 1A, or a mechanism thatsucks the web W toward the center of the rotation device 1A by a vacuum.Where the air blowing mechanism is employed, only one directioningsection 12′ may be provided, or a plurality of orientation sections 12′may alternatively be provided as illustrated in FIG. 19A. Also, wherethe slack portion thrusting mechanism is employed, only one directioningsection 12′ may be provided, or a plurality of orientation sections 12′may alternatively be provided. By providing a plurality of orientationsections 12′, it is possible to reliably fold in the slack portion W1toward the center of the rotation device 1A. The width of thedirectioning section 12′ (the length thereof in the directionperpendicular to the surface of the sheet of the figure) can be set to avalue (a length in the direction perpendicular to the surface of thesheet of the figure) according to the width of the web W.

Moreover, one or more suction holes 11 may be provided on each of theside surfaces of the pads 9 _(i) by which the web W is to be sandwiched,i.e., on the side surfaces of each pad that face the side surfaces ofthe adjacent pads, so that the slack portions W1 of the web W are laiddown along the side surfaces of the pads 9 _(i).

The direction in which the web is to be folded may be the direction inwhich the web runs or the opposite direction. For example, in a casewhere the circumferential velocity of the trailing one of two pads thatsandwich the web therebetween is higher than that of a conveyer in thevicinity of the hand-over position SP, the web is folded by the trailingpad in the running direction. In such a case, the leading pad is onlyrequired to move so as not to interfere with the movement of thetrailing pad. In a case where the circumferential velocity of theconveyer is higher than that of the leading pad in the vicinity of thehand-over position SP, the web is folded by the leading pad in thedirection opposite to the running direction.

In the present embodiment, a side surface of each pad 9 _(i) in thecircumferential direction forms a folded portion. Specifically, the sidesurfaces of two adjacent pads 9 ₄ and 9 ₅ that are facing each other inthe circumferential direction come close to each other at the hand-overposition SP so as to fold in two the web W therebetween, thereby formingthe folded portion W2.

An applicator (an example of a fold-holding section) 13 for applying anadhesive such as a hot melt resin may be provided on the receiving side,as illustrated in FIG. 19A. The applicator 13 applies an adhesive on oneor both of another web Wo and the web W to be folded so as to bond thewebs Wo and W together, thereby making it easier to maintain the shapeof the folded portion W2.

Alternatively, in the present embodiment, a conveyer as illustrated inFIG. 20 may be used to maintain the shape of the folded portion W2.

Moreover, the directioning section 12′ may suck in the slack portion W1by a stream of air as illustrated in FIG. 20. The suction by thedirectioning section 12′ forms the slack portion W1 into a shape that isprotruding from the rotation device 1A. The suction of the web W, thenumber of the directioning sections, etc., may be set as those for thedevice of FIG. 19A.

Referring to FIG. 20, the slack portion W1 of the web is sandwichedbetween the pad 9 _(i) and the belt 31′ of the conveyer 30′, therebyforming the folded portion W2. Another example of the fold-holdingsection provided on the receiving side may be, for example, a meshedbelt 31′ of the conveyer 30′ capable of sucking an air therethrough bywhich the folded web W is received, wherein the web W is sucked by anair 100, as illustrated in FIG. 20, so as to maintain the shape of thefolded portion W2. Instead of the meshed belt 31′, a belt 31′ includinga plurality of holes therein may be used. Moreover, the fold-holdingsection may alternatively maintain the shape of the slack portion W1 byusing an electrostatic charge, or the like.

A bellows-shaped folding device for performing a bellows-shaped foldingprocess, which is a modified version of the Z-shaped folding process,will be described with reference to FIG. 19B to FIG. 19D. Thebellows-shaped folding device is capable of folding the slackened web Wat a plurality of positions.

The bellows-shaped folding device includes, in addition to the elementsof the folding device of FIG. 19A, a plurality of plates P_(i) betweenadjacent pads 9 _(i−1) and 9 _(i). As illustrated in FIG. 19D, theplates P_(i) are pivotally connected to one another and to the pads 9_(i) via joints J_(i). For example, the plate P₁ is pivotally connectedto the pad 9 _(i−1) via the joint J_(i), and the adjacent plate P₂ ispivotally connected to the plate P_(i) via the joint J₂.

Each plate P_(i) is capable of sucking the web W. Each plate P_(i) mayinclude at least one suction hole, through which the web W is sucked. Insuch a case, each plate P_(i) may be meshed. Moreover, thebellows-shaped folding device may have each plate P_(i) charged with afirst charge and the web with another charge that attracts the firstcharge, so as to attract the web W onto the plate P_(i).

Referring to FIG. 19C, as the interval between adjacent pads 9 _(i−1)and 9 _(i) is shortened, the plurality of plates P_(i) that have been ina spread formation are turned into a bellows-like shape. The jointsJ_(i) between the plates P_(i) may restrict the angle by which theconnected plates P_(i) can pivot in order to form a predeterminedbellows-like shape in the web. For example, an elastic member 40′ may beprovided between the plates P₂ and P₃ as illustrated in FIG. 19D so asto restrict the angle by which the plates P_(i) can pivot.

As the interval between adjacent pads 9 _(i−1) and 9 _(i) is shortened,the web W attracted onto the plates P_(i) is bent so as to conform withthe shape of the plates P_(i). The slackened web W is folded so as tohave top portions and bottom portions and is transferred onto theconveyer 30′.

The folded web W may be transferred onto the conveyer 30′ after theinterval between adjacent pads 9 _(i−1) and 9 _(i) has been shortenedand before the interval therebetween reaches its maximum value. In sucha case, a triangular prism-shaped wall Tw is formed as illustrated, forexample, in FIGS. 22 and 23.

FIG. 21 illustrates another example of a folding device. In the figure,a pair of first rolls 21 and 21 having a high transfer speed v1 areprovided upstream, with respect to the transfer direction, along the webW, and a pair of second rolls 22 and 22 having a low transfer speed v2are provided downstream along the web W.

Since the velocities satisfy v1>v2, the slack portion W1 is formedbetween the first rolls 21 and the second rolls 22. The direction inwhich the slack portion W1 is folded is determined by the directioningsection 12. In the present embodiment, the directioning section 12includes two bars 12 a and 12 b extending in the width direction of theweb W. Broken lines in the figure represent the respective traces of thetwo bars. The second bar 12 b moves after the first bar 12 a moves,thereby forming the folded portion W2. Since the web W is made of arelatively light material such as non-woven fabric, pulp or a syntheticresin, the web W can easily be supported by the bars 12 a and 12 b withonly one end thereof being fixedly supported. After the folded portionW2 is formed, the second bar 12 b retracts toward the first rolls 21before it is caught between the second rolls 22. Moreover, the first bar12 a can move in the width direction of the web W so as to extend beyondthe edge of the folded portion W2.

It is possible to produce a disposable worn article, including a napkin,a diaper and pants, with a wall formed therein, by employing the“Z-shaped folding process” as described above.

FIG. 22 illustrates an example of a top sheet of a napkin, in whichbroken lines represent a web. In FIG. 22, the walls Tw are formed in atop sheet T so as to extend in a direction generally perpendicular tothe running direction X of the top sheet T being produced. With therunning direction X being a transverse direction, elongated walls Tw canbe formed along the opposing sides of the napkin.

FIG. 23 illustrates a top sheet (web) W of a diaper or pants beforecutting. By slacking the web W using the folding method described above,the walls Tw can be formed in a direction Y transverse to a runningdirection X of the web Was illustrated in the figure. In other words,the longitudinal direction Y of the walls Tw is transverse to therunning direction X of the web W. The longitudinal direction of anabsorbent (core) Co denoted by a broken line is transverse to therunning direction X of the web W (i.e., the production line is of aso-called “transverse flow” type). Therefore, it is possible to producea diaper or pants in a transverse flow type production by cutting theweb W in a direction transverse to the running direction (the Xdirection) as indicated by a two-dot chain line. As is well known in theart, a liquid impermeable back sheet, in addition to the absorbent Co,can be layered on the liquid permeable top sheet. The wall Tw mayalternatively be formed on the absorbent Co. The wall Tw may be formedin the vicinity of an end of the absorbent Co, or a plurality of wallsTw may be formed in the vicinity of the end of the absorbent Co.

While the web is folded in a certain direction in the examplesillustrated in FIG. 19A to FIG. 19D and FIG. 20, every other foldedportion may be folded back in the opposite direction, for example, so asto form the walls Tw illustrated in FIG. 22 and FIG. 23.

An elastic member for making the worn article better fit to the wearermay be provided along the wall Tw. For example, a mechanism forattaching an elastic member that is extending in the direction Ytransverse to the running direction X of the web W onto the web (e.g., awidening mechanism as described in Japanese Patent Application No.12-028945) may be employed so as to provide an elastic member inside thewall Tw. The elastic member may be made of at least one flat or cordrubber.

The wall Tw of a disposable worn article such as a napkin, a diaper orpants as described above may be formed by the bellows-shaped foldingprocess. Moreover, in a disposable worn article such as a napkin, adiaper or pants, a plurality of top portions and bottom portions may beformed on the absorbent Co through the bellows-shaped folding process.In such a case, excrement is drawn into the bottom portions, therebyreducing a leak from the worn article.

FIG. 24 is a diagram illustrating an example of a plurality of walls Twformed on each absorbent Co through the bellows-shaped folding process.The walls Tw may be positioned on the absorbent Co directly, orindirectly via a sheet, or the like. The sheet may be a continuoussheet, or at least one sheet may be layered between a plurality of wallsTw and an absorbent. In order to fix the walls Tw at predeterminedpositions, bottom portions Vw of the walls Tw are preferably flat.Specifically, the area over which the bottom portions Vw of the walls Twcontact the sheet or the absorbent Co is preferably 50% or more of thetotal area of the sheet or the absorbent Co.

FIG. 25 is a diagram illustrating a portion of a bellows-shaped foldingdevice 100 for forming bottom portions Vw that are generally flat. Thebellows-shaped folding device 100 includes a plurality of pads 9 _(i),at least one dummy pad 101, and a plurality of generally V-shaped platepairs 102. Each of the generally V-shaped plate pairs 102 includes twoplates P and P, and each plate P is capable of pivoting with respect tothe other about the link between the plates P and P. One end of eachgenerally V-shaped plate pair 102 is connected to the dummy pad 101 orthe pad 9 _(i).

At least one of the pads 9 _(i), the dummy pad 101 and the generallyV-shaped plate pair 102 is capable of sucking the web W onto the surfaceof the plates P and P and the surface of the top portion of the dummypad 101. Where the width Wd of the bottom portion of the wall is 1 cm orless, the web W may be sucked by using only the pads 9 _(i) and thegenerally V-shaped plate pairs 102. When the width Wd of the bottomportion of the wall is so small, the web W can be attracted and securedonly by suction by the pads 9 _(i) and the generally V-shaped platepairs 102.

Preferably, the surface configuration of the pads 9 _(i) and the dummypads 101 is such that the surfaces of the pad 9 _(i) and the dummy pad101 contact the conveyer when handing over the folded web W to theconveyer.

Moreover, it is possible to attach at least one elastic member to a webin an intermittent manner by employing the “Z-shaped folding process”.Accordingly, a disposable worn article including a web with at least oneelastic member attached thereto in an intermittent manner can beproduced by employing the “Z-shaped folding process”.

Specifically, at least one elastic member is bonded to a web, with aslack portion having been formed therein through the “Z-shaped foldingprocess”, so that the elastic member extends across the slack portion,as illustrated in FIG. 26A. Then, the elastic member F is cut off in thevicinity of a position between one edge W11 of the slack portion W1 ofthe web W and the other edge W12 of the slack portion W1. The elasticmember F may be cut by using a straight cutter or an embossing roll. Astraight cutter, an embossing roll, or the like, can cut off the elasticmember through the application of heat, pressure, or a combinationthereof, for example. U.S. patent application Ser. No. 09/891,034, PCTInternational Publication WO00/76444 and Japanese Laid-Open PatentPublication No. 2000-26015 are incorporated herein by reference, withrespect to a cutting method using an embossing roll. Upon the cuttingoff of the elastic member, the slack of the web is eliminated.

FIG. 26B is a diagram illustrating the web W after cutting off theelastic member F and eliminating the slack. In this way, the elasticmember can be provided on the web W except for a portion W3 that hasbeen a slack portion. Thus, it is possible to provide the web W withpieces of at least one elastic member F that are spaced apart from oneanother at a constant interval.

An elastic member F may be sandwiched between a first web that has beensubjected to the “Z-shaped folding process” and a second web. FIG. 27illustrates an example of a device for intermittently introducing anelastic member F between a first web W that has been subjected to the“Z-shaped folding process” and a second web Wo.

The device applies an adhesive 201 on at least a portion of at least oneof the first web and the second web. Then, nip rolls 200 secure thefirst web W, the elastic member F and the second web Wo with respect toone another. The laminate obtained by the nip rolls 200 is passed to anembossing roll 203. The embossing roll 203 is provided with a pluralityof protrusions that cut off at least one the elastic member F of thelaminate along with a portion of the second web Wo. The tip of eachprotrusion may be sharp as disclosed in U.S. patent application Ser. No.09/891,034.

The second web Wo may be provided with a slit at each positioncorresponding to a slack portion W1 of the first web W. When the slackW1 of first web W is eliminated, i.e., when the laminate on which theelastic member F has been cut off is placed under a tension, the secondweb Wo is also cut off along the slit.

Alternatively, the second web Wo may include a slack portion. In such acase, the first web W, the elastic member F and the second web Wo arebonded together so that the position of the slack portion of the firstweb W corresponds to the position of the slack portion of the second webWo. Only the elastic member F may be cut off. For example, it ispossible to cut off only the elastic member F by employing an elasticmember F whose melting point is lower than that of the second web Wo andembossing the laminate while heating the embossing roll 203 to apredetermined temperature. It is possible to cut off only the elasticmember F with substantially no heat-induced alteration to the second webWo if the temperature of the embossing roll 203 is higher than themelting point of the elastic member F and lower than the melting pointof the second web Wo. Moreover, even when the temperature of theembossing roll 203 is higher than the melting point of the second webWo, it is possible to cut off the elastic member before holes arecreated in the second web if the running velocity of the laminate ishigh.

FIG. 28 is a diagram illustrating an example of a pants-shaped diaper N,which is a disposable worn article, being spread out. The pants-shapeddiaper N includes an absorbent Co, a front flap 300 and a back flap 301.The front flap 300 and the back flap 301 include a waist gather Fw thatclosely fits to the wearer around the waist, and a fit gather Fb thatfits to the abdominal part of the wearer. The fit gather Fb is generallyabsent in a portion where the pants-shaped diaper and the absorbent Cooverlap with each other. If there is an elastic member F in theoverlapped portion, the absorbent Co shrinks, thereby deteriorating thecomfort to the wearer. The front or back flap 300, 301 can be producedby attaching an elastic member to a web in an intermittent manner byusing the “Z-shaped folding process” described above. Note that thepants-shaped diaper may include a wall as described above. The wornarticle described above may of course be an article other than apants-shaped diaper, such as a diaper with adhesive tapes.

The elastic member described above may be a polyurethane fiber, anatural rubber or a synthetic rubber, The polyurethane fiber may beLycra® manufactured by EI du Pont de Nemours and Company. The elasticmember may be in the form of a cord, a string or a net, or have a flatshape. As a net-shaped elastic member, Rebound® manufactured by CONWEDPLASTICS may be used.

As described above, in the rotation device of the present invention,rotation member is provided so as to allow a guide to rotate, with theguide being provided with a plurality of moving sections, whereby eachmoving section can slide independently. Therefore, the friction betweenthe guide and the moving sections is significantly reduced, and thus itis possible to rotate the moving section continuously over a long periodof time. Moreover, a plurality of moving sections can be providedwithout being spaced apart from one another in the axial direction,whereby the size of the device can be reduced.

Moreover, when a plurality of moving sections are provided in the axialdirection with a bridging section extending between the moving sections,the bridging section is stabilized because the bridging section can thenbe supported at two positions.

Moreover, with the folding method or the folding device of the presentinvention, it is possible to easily and efficiently form a foldedportion or a wall in a direction transverse to the direction in whichthe first web is transferred.

A worn article including a wall formed as described above has differentcharacteristics from those of a worn article having a wall that isparallel to the direction in which the first web is transferred.

Various other modifications will be apparent to and can be readily madeby those skilled in the art without departing from the scope and spiritof this invention. Accordingly, it is not intended that the scope of theclaims appended hereto be limited to the description as set forthherein, but rather that the claims be broadly construed.

1-3. (canceled)
 4. A disposable worn article, comprising a member, themember being obtained by: forming a slack portion, on which no tensionis applied, in a continuous member in a running direction thereof, thecontinuous member comprising at least one of a top sheet, an absorbentand a back sheet; folding the slack portion so as to form a wall that istransverse to the running direction; and cutting the continuous memberwith the wall formed thereon. 5-11. (canceled)